1. Field of the Invention
This invention relates to bucket wheels for handling bulk materials and more particularly, it relates to compartmented bucket wheels.
2. Prior Art:
In compartmented bucket wheels a plurality of buckets, mounted on the periphery of a drum rotated about a horizontal axis, scoop up material which slides radially inward into compartments within the drum as the bucket travels upward. Diagonal deflection surfaces within the compartments direct the material laterally out of the drum onto a conveyor or other suitable receiving device as the bucket approaches the top of the arc.
Whether the drum is cylindrical or in the shape of a regular polygon in vertical section, and whether separate compartments are provided for each bucket or for a group of buckets, the walls separating the compartments generally converge in the radially inward direction. Thus a funneling effect is produced as the material slides downward and laterally out of the drum. Even in U.S. Pat. No. 992,346 wherein the walls of the compartments are not radially oriented, the material is funneled down to a small lateral opening.
This funneling effect is a limiting factor in the capacity of the prior art bucket wheels. Sufficient time must be allowed for the material to slide out of the compartments which, in turn, limits the speed of rotation of a given bucket wheel. This becomes even more of a problem when the material being handled does not have free-flowing characteristics.
U.S. Pat. No. 3,020,656 suggests that the front walls of the compartments diverge laterally to assist in discharging material, however, the compartments still converge in the radial direction which porduces the funneling effect. As in the other prior art bucket wheels, the front corner of the compartment drops below the level of the chute directing material to the receiving conveyor before all of the material has been discharged, thus resulting in the trapping of a certain amount of material and wasteful carryover.